Battery run d-c motor speed control, charging and steering systems

ABSTRACT

A first system for energizing a d-c motor includes a switching network for passing energy to and from a battery, and to the d-c motor. The battery can energize the motor over the switching network, and the battery can be recharged over a first channel supplied with a-c energy which is rectified and passed through the switching network to the battery. A second channel provides power control to regulate the level of d-c energy to the motor and thus control motor speed, and also provide an indication of the battery power available. A third channel energizes an r-f oscillator over the switching network from the battery. The a-c voltage from the r-f oscillator is rectified, filtered and applied to an alternate d-c motor. Another system includes a pair of d-c motor groups, with two separate channels for energizing each motor group simultaneously or independently. This provides a steering function in addition to the optional battery charging speed control arrangements already described.

ilnited States Patent [191 Lee 3,736A30 May 29, 1973 Primary ExaminerJ.D. Miller Assistant Examiner-H. Huberfeld Attorney-James J. Jennings,Jr.

[76] Inventor: .100 C. Lee, c/o Temptron, Inc.,

1684 5. Wolf Road, Wheeling, m. [57] ABSTRACT 60090 A first system forenergizing a d-c motor includes a switching network for passing energyto and from a [22] Filed 1972 battery, and to the d-c motor. The batterycan ener- [21] App]. No.: 225,565 gize the motor over the switchingnetwork, and the battery can be recharged over a first channel suppliedwith a-c energy which is rectified and passed through [52] U.S. Cl...3l8/5l, 3l8/3lg;/,5391 the Switching network to the battery A SecondChan [51] Int Cl 02m 3/14 H02p 5/46 nel provides power control toregulate the level of d-c [58] Fie'ld 318/51 105 106 energy to the motorand thus control motor speed, 318/107 and also provide an indication ofthe battery power 57 321/2 available. A third channel energizes an r-foscillator over the switching network from the battery. The a-c [56]References Cited voltage from the r-f oscillator is rectified, filteredand applied to an alternate d-c motor. UNITED STATES PATENTS Anothersystem includes a pair of d-c motor groups, with two separate channelsfor energizing each motor 3,551,774 12/1970 Rusch ..318/139 X groupsimultaneously or independently. This provides 22 32 a steering functionin addition to the optional battery t charging speed controlarrangements already 3,702,959 11/1972 LeGloan ..3l8/l39 described 18Claims, 9 Drawing Figures CHANNEL 3: 0c TO AC SWITCHING '2 o 48 2o 45NETWORK 47 46 BATTERY MOTOR FILTER CONVERTER EBHIGCHFREQ.

120v l3 mpur VOLTAGE HIGHFREQ h ouTPuT E 60 Hz RECTIFIER REGULATOR osc.g 8 RECTIFIER 22 14 l5 l6 21 IO CHANNEL I7 5L4 MOTOR AC TO 0c DR'VERPOWER 39 I! fiSfiEMFTE'RIG.) AMPL'F'ER 37 am 27 26 L l CONTROL 25 ANDINDICATION LAMP 1 HOTO- METER CELL Patented May 29, 1973 3,736,480

5 Sheets-Sheet 3 FIG. 4A

RECTIFIER FIG.

Patented May 29, 1973 5 Shanta-Sheet N2 NE A 3 B J 9N m v. m ma mnCSuEums? 526m m n ma W W... wz= o.:;m 9m mm. FUN QM m N m. v2 mH 9: v2 N2 h r1 m wt m :2 vm o2 wow *9 wd v C3 om. .BN N9 6N :N NE wt mm. com w new 1*m v8 n 2.. m 2 nomow 09 w; 5y w! m! li mmioa BATTERY RUN D-C MOTOR SPEEDCONTROL, CHARGING AND STEERING SYSTEMS BACKGROUND OF THE INVENTION Thereare many areas in which small, fractional horse-power d-c motors areuseful. One such area is the sporting goods field, in which smallelectrical motors are used on boats for trolling. However some provisionmust be made for recharging the battery in an efficient manner when theboat returns to the dock. It is also desirable to have some form ofspeed control, even at the low operating levels of trolling motors. Atthe present time an efficient solution of these problems has not beenattained, and it is therefore a prime consideration of the presentinvention to produce an efficient d-c motor energization system witheffective battery recharging, with the lowest ratio of volume [orweight] to the volt-ampere capacity, and with power level control of theenergy passed to the motor to regulate the motor speed.

It is another important consideration of the invention to provide anindication of two conditions, that power is being supplied to the powerstages, and that the power stages are in fact operating.

Still another important consideration is the provision of atwo-motor-group system, to allow steering as well as propulsion.

SUMMARY OF THE INVENTION A system for regulating energization of a d-cmotor from a battery, and also for regulating charging of the battery,comprises in a first embodiment separate channels for regulating thedifferent functions. A switching network is coupled both to the batteryand to the motor to regulate the passage of energy to the motor, and toand from the battery. A first channel is coupled between an a-c inputline and this switching network. The first channel includes an inputrectifier coupled to the a-c input line, and an oscillator or inverterfor providing a-c energy as it receives d-c energy from the inputrectifier. This a-c energy is passed over first and second windings of atransformer to another rectifier, which converts the energy to d-c andpasses it to the switching network for charging the battery. A secondchannel is connected to receive constant level d-c energy from theswitching network and return a variable level energy to regulate themotor energization level and thus control motor speed. The secondchannel may include an indicator feature which only responds to thepresence of two conditions, the receipt of d-c energy from the switchingnetwork, and the suitable operation of the second channel for providingthe variable power level. Another feature which may be incorporated inthe first channel is a feedback arrangement which senses the flux levelin the transformer over a feedback winding, thus accomodating operationto changes in load and making the regulation function independent oflosses in the oscillator or inverter. A third channel can be added toreturn energy from the battery over the switching network and anotheroscillator-converter-filter arrangement for energizing a second d-cmotor.

In accordance with another aspect of the invention, a pair of motors canbe utilized for situations where, as in the propulsion of a boat,steering can be accomplished with the motors driven at different speeds.Two separate channels are then provided, one for regulating theenergization of each motor. An appropriate steering switch is utilizedto obtain the steering function.

THE DRAWINGS In the several figures of the drawings, like referencenumerals identify like elements, and in the drawings:

FIG. 1 is a block diagram of a first embodiment of the inventionincluding a switching network for regulating the power transferfunctions;

FIG. 2 is a schematic diagram setting out circuit details of a portionof the system shown generally in FIG.

FIGS. 3A, 3B, and 3C are graphical representations useful inunderstanding the operation of the system shown in FIG. 2;

FIGS. 4A and 4B are schematic diagrams which, taken together, illustratea system arrangement for the two-motor embodiment with steering; and

FIG. 5 is a schematic diagram of an oscillatorconverter arrangement forpowering a universal motor from the system battery.

GENERAL SYSTEM DESCRIPTION FIG. 6 shows an embodiment in which arheostat replaces Channel 2 of FIG. 1.

FIG. 1 shows a general system arrangement for power transfer over aswitching network 10 to energize either a first d-c motor 11 or a secondd-c motor 12. With volts, 60 hertz energy available, input line 13 canpass this energy over the components in Channel 1 including inputrectifier 14, voltage regulator 15, oscillator 16, primary winding 17and secondary winding 18 of the multiwinding transformer 20, and outputrectifier 21 to the switching network 10. The d-c energy at the outputside of rectifier 21 can be passed over network 10 and utilized tocharge battery 22. During the charging operation voltage control inChannel 1 is provided by a circuit including a feedback winding 23 oftransformer 20, which passes a signal over line 24 to voltage regulator15 to insure the appropriate voltage level is established for theoscillator. The term oscillator," as used herein and in the appendedclaims, means a circuit for providing an r-f a-c output signal whenenergized by a d-c voltage. Thus inverter, switching circuit, or othersimilar terms are generally interchangeable with oscillator" as usedherein.

An important part of the energy supply arrangement is the provision ofthe power level control and indication arrangement, designated Channel 2in the lower part of the drawing. With the switches in network 10 in theappropriate positions, the d-c energy from rectifier 21 is passedthrough network 10 and over input line 25, resistors 26, 27 andreference line 28 to energize a driver amplifier stage 30, which in turnpasses its output pulses to a power amplifier stage 31. The energy frompower amplifier 31 is then returned over output line 39 and network 10to drive motor 11. In that the motor represents an inductive load, thepulse out-put from power amplifier 31 is averaged in the loadinductance, and the duty cycle of the driver amplifier in effectregulates the motor speed. In turn, this duty cycle is set bypotentiometer 32, connected in parallel with a Zener diode 33 near theinput side of the driver amplifier stage 30. In one embodiment with a 12volt d-c energization on line 25, Zener diode 33 was provided with an8.2 volt rating so that current would only flow through resistors 26, 27to energize driver amplifier 30 when the supply from rectifier 21 orbattery 22 is sufficiently high to forward bias transistor 34, theemittercollector path of which is coupled in series with a lamp 35 andthe emitter-collector path of a second transistor 36. The out-put of theSchmitt trigger driver stage 30 is sensed, over diode 37 and resistor38, so that transistor 36 is only rendered conductive when there isactually drive from the driver amplifier 30 to the power amplifier 31.Thus the illumination of lamp 35 indicates both that energy is beingsupplied to driver amplifier 30, and that this stage is in fact passingoutput current to the power amplifier.

As the setting of potentiometer 32 is varied, the duty cycle and thefrequency of the Schmitt trigger circuit 30 is correspondingly modifiedand the average value of the signal supplied to the base of transistor36 is varied. Thus the intensity of the radiation from lamp 35 isproportional to the duty cycle of the driver amplifier stage 30. Aphotocell 40 is positioned so that the radiation strikes it and providesa signal to an RMS meter 41 for a visual indication of the amplitude ofthe energy being supplied from the driver amplifier to the poweramplifier. If desired, an alarm 42 can be coupled to the meter circuitto be energized if the energy transfer level drops below a predeterminedminimum value. This can be done by a set of contacts on the meteritself, which contacts are movable to close a circuit at any preselectedcurrent level.

The third channel, in the upper portion of FIG. 1, provides for a supplyof d-c energy from battery 22 in a right-to-left direction as viewed inthe figure to energize the second motor 12. With the individual switchesin switching network in the appropriate positions, d-c energy frombattery 22 passes over this network to energize high-frequencyoscillator 45, which can be essentially the same type as oscillator orinverter 16 in the first channel. A-C energy is passed over primarywinding 46 and a secondary winding 47 of transformer 20, rectified in aconverter stage 48, filtered in stage 50 and then applied to energizemotor 12. This allows for the alternate energization and the operationof a second motor, such as a universal type d-c motor. Details of acircuit suitable for Channel 3 are shown in FIG. 5, and will bedescribed hereinafter.

DETAILED DESCRIPTION OF THE INVENTION Circuit details of the a-c to d-cChannel 1 are shown in the left portion of FIG. 2. Single phase 120volts, 60 hertz energy is received over conductors 13a, 13b and, whenthere is a ground wire, over 130. These conductors are coupled over theconnectors 52a, 52b and 520 to the corresponding circuit conductors 53,54 and 55. Conductor 55 is connected directly to a chassis ground. Theother conductors 52 and 53 are coupled to the input connections of inputrectifier bridge 14, the output connections of which are coupled to theenergizing conductors 56 and 57. A filter capacitor 58 is connected asshown between these conductors 56, 57.

At the input side of voltage reulator circuit 15, a series circuitcomrising diodes 60, 61 and resistor 62 is connected between conductors56, 57. The base of a PNP type transistor 63 is coupled to the commonconnection between diode 61 and resistor 62, and the emitter of thistransistor is coupled through a resistor 64 to conductor 56. Thecollector of transistor 63 is coupled both to the base of an NPN typetransistor 65 and to the collector of another NPN type transistor 66,the emitter of which is copuled through a Zener diode 67 to conductor57. The collector of transistor 65 is coupled to conductor 56, and theemitter of transistor 65 is coupled to the base of another NPN typetransistor 68, the emitter of which is coupled to conductor 70. Aresistor 71 is connected between conductor 70 and the common connectionbetween the emitter of transistor 66 and Zener diode 67. The base oftransistor 66 is copuled over feedback conductor 24 to receive thevoltage regulating signal. That is, transistor 66 acts as a variableimpedance under the regulation of the signal on line 24 to effect aregulation in the output voltage level between conductors 70, 57 as afunction of the feedback signal. This output voltage is smoothed by thefilter capacitor 72 connected as shown between conductors 70 and 57.

In high frequency (about 30,000 hertz) oscillator circuit 16, resistors73, 74 and capacitors 75, 76 are connected in series between conductors70 an S7. The NPN type transistor 77 in this circuit has its collectorcoupled to conductor 70, and its base connected to the common connectionbetween resistors 73, 74. Its emitter is coupled through a variableresistor 78 and a resistor 80 to a tap 81 on the primary widing 17. Thelower end of this winding is copuled to conductor 57, and the upper endprovides a feedback signal over conductor 82 to the common connectionbetween capacitors 75, 76.

Variable resistor 78, coupled to the emitter of transistor 77, performsan important current-limiting function in this circuit. There is acertain back emf on the transformer primary winding between terminal 81and the lower end of winding 17, and the current flow due to thisvoltage is limited by the variable resistor 78. It is noted that thiscurrent is not necessarily constant. As the load increases and thesecondary winding 18 is loaded, current through the primary and thusthrough the oscillator circuit correspondingly increases. without excessloading the oscillator circuit 16 produces well-defined triangularpulses such as represented generally'in FIG. 3A. Under heavy loadingconditions, this wave shape gradually deteriorates as depicted generallyin FIG. 3B, which is a graphical representation of interruption of thecircuit which would otherwise maintain the voltage reference between thebase and the emitter of transistor 77. Interruption of this circuitstops oscillation. Because the series regulator circuit 15 is a highimpedance source, the field of transformer 20 collapses and nothingfurther occurs. Accordingly the importance of the variable resistor 78in this circuit is manifest. FIG. 3C shows the collector current oftransistor 77 due to the back emf caused by tank circuit 76, 17.Resistor is chosen to prevent negative current flow through resistors 78and 80. The elimination of this negative current prevents damage oftransistor 77.

Considering now the feedback circuit from feedback winding 23 oftransformer 20, the opposite ends of this winding are coupled overrespective diodes 83, 84, and conductor 85 to the upper end of apotentiometer 86. The lower end of this potentiometer is coupled over afixed value resistor 87 and conductor 88 to the center tap of secondarywinding 23. A filter capacitor 90 is connected between conductors 85, 88as shown to filter the rectified d-c voltage supplied to potentiometer86. The level of the feedback signal is adjusted by setting the arm ormovable tap of potentiometer 86 to regulate the level of the feedbacksignal applied over conductor 24 to the base of transistor 66 in theseries regulator circuit.

The particular feedback arrangement is important for several reasons.For example, if the output of the series regulator were sensed and thissignal utilzied to regulate its operation, the Channel 1 circuit wouldnot compensate either for losses in the circuit of oscillator 16, or forfluctuations in the load on the other side of secondary winding 18.Better regulation is thus achieved with this arrangement. The loadvoltage for charging the battery 22 can be compensated in thisregulating arrangement. This is because changes in the load demand willprovide a corresponding change in the flux density in the transformercore 20, effectively changing the signal fed back over line 24 to theseries regulator 15.

Considering now the circuit including switching network 10, secondarywinding 18 has its opposite end portions coupled through diodes 92, 93and over conductor 94 to one fixed terminal 95 of a fixed-variableswitch 96, which includes another fixed contact 97 and a movable contactportion 98. The movable contact 98 is ganged to another movable contact100 of the same switch 96, shown engaging fixed contact 101 anddisplaceable to engage the other fixed contact 102 of this set. In thevariable position of switch 96 as shown, the output power from poweramplifier 31 is supplied over conductor 39 to conductor 103, and also tomovable contact 100 of the fixed-variable switch 96. Conductor 103 iscoupled to fixed contact 104 of a bypass switch 105, which includes amovable contact 106 shown engaging a fixed contact 107. In the positionshown switch 105 completes the circuit for supplying energy overconductor 25 to energize the power amplifier 31, driver amplifier 30 andthe other components shown in the lower portion of FIG. 1. Whilerepresented as a simple ground connection in FIG. 1, of course there isanother d-c conductor for this energy supply and return circuit, whichconductor is referenced 108 in FIG. 2. This circuit is returned over adiode 110, a meter 111, conductor 112 and a resistor 113 to the centertap connection of secondary winding 18. Conductor 112 is also coupled tothe negative terminal of battery 22 and to two of the fixed connectionsof the forward reverse switch 114. This switch includes a first contactset with a movable contact 115 and a pair of fixed contacts 116, 117,and a second contact set with another movable contact 118, and fixedcontacts 119 and 1120. Conductor 112 is copuled to the fixed contacts117 and 119. Fixed contact 120 of the lower set is coupled both to fixedcontact 116, and to fixed contact 101 of the fixed-variable switch. Allthe switches shown in the upper right hand portion of FIG. 2 can beconsidered as individual switch components of the switching networkreferenced 10 in the general explanation of the system.

As shown switch 96 is in the variable" position, in which the powerlevel in the driver amplifier and power amplifier (FIG. 1) can be variedto control the motor speed. In this position, energy is supplied bybattery 22 over contacts 97, 98, 106, 107 and conductor 25 to theChannel 2 components, including the driver amplifier 30 and poweramplifier 31. The variable power level, regulated by the setting ofpotentiometer 32, is provided over output conductor 39 to switchcontacts 100, 101, 116, 115, motor 11, contacts 118, 119 and conductor112 back to the negative pole of the battery.

Thus the motor can drive a boat or other load and its speed will bemaintained in accordance with the setting of potentiometer 32. If it isdesired to drive the load at a constant speed, without the variablecontrol of this potentiometer, movable contact 106 is displaced from itsindicated position to engage fixed contact 104 and complete a bypasscircuit over conductor 103 to energize the motor in an obvious manner.

To complete a circuit for charging battery 22 over the Channel 1components shown in the left portion of FIG. 2, switch 96 is displacedso that movable contacts 98, 100 now engage fixed contacts and 102. Withd-c energy from the circuit coupled to the secondary winding 18 providedas shown, one side of the circuit is coupled over resistor 113 andconductor 112 to the negative pole of battery 22. The other connectionis extended over conductor 94, contacts 95, 98, 106, 107, conductor 25,through the driver amplifier and power amplifier, over conductor 39,contacts and 102, to the positive pole of battery 22. Of course if it isdesired to bypass the controlled power circuit in the second channel andprovide full power charging, movable contact 106 can be displaced toengage fixed contact 104 and effectively shunt the controllable powerchannel. The forward-reverse switch 114 operates in an obvious manner toreverse the effective polarity of the d-c energy supplied to motor 11,thus reversing its rotation and the direction in which the load isdisplaced.

Considering now the two-motor showing in FIGS. 4A and 4B, in FIG. 4A arectifier circuit 21 is illustrated providing d-c energy betweenconductors and 131. It will become apparent that this system, with thatin FIG. 48, can charge battery 22, energize left motor 11 and/or rightmotor 9 directly from the battery, or from the variable power levelcontrol depicted in FIG. 4B. It should be understood that the term left,as used in conjunction with motor 11, indicates the motor 11 can bepositioned on the left rear of a boat, with the right motor 9 positionedat the right rear. The terms left and right designate the motorpositions with respect to each other at the stern. Thus if both motorsare energized at the same level, the boat will move through the waterevenly. If the left motor 1 1 is energized at a level greater than thatof the right motor 9, then the craft will turn gradually to the right.The same principles are true if the left and right motors are installedin an automotive vehicle, in that a drive train on one side of thevehicle turning at a speed greater than that on the other side willcause the vehicle to turn. The same skid-steer principle is applicableto installation in a tracked vehicle, such as an amphibious vehicle orone with tank-like treads, and in underwater diving equipment poweredwith electric motors. Those skilled in the art will readily appreciatethe universal application of these principles.

In the upper portion of FIG. 48, a switching circuit 132 and a poweramplifier circuit 133 provide energy at a controlled level over outputconductor 134 for application through the illustrated switching networkto left motor 1 1. In like manner a second switching circuit 135 and itscorresponding power amplifier circuit 136 provide output power at aregulated level over conductor 137 for application, through theswitching arrangement, to energize right motor 9. Because switchingcircuit 132 is the same as its counterpart 135, and power amplifiercircuit 133 is in all respects identical to power amplifier circuit 136,the schematic details of the switching circuit and power amplifier forthe left motor channel will suffice to explain circuit interconnectionand operation for both.

With charge-run switch 140 in the run position as shown, on-off switch141 can be closed to complete a circuit from the positive pole ofbattery 22 over switch 141, conductor 142, fixed contact 143 and movablecontact 144 of the chargerun switch, conductor 146, diode 147 andresistor 148 to another energizing conductor 150. Energy is passed overconductor 150 to the other switching circuit 135 in the channel for theright motor 9. At the same time the negative pole of battery 22 iscoupled over conductor 131 and diode 151 to common conductor 152 in thepower amplifier and switching circuit for the left motor. The negativepole battery connection is also extended over conductor 153'to thecapacitor 154 in the output stage of power amplifier 136. The connectionof this capacitor and the inductor 155 will be understood from theexplanation in connection with power amplifier 133.

Just to the left side of switching circuit 132, a Zener diode 156 iscoupled between conductors 150 and 152 to provide a well regulatedvoltage for the switching circuits 132 and 135. A filter capacitor 157is also coupled between conductors 150, 152.

In the right hand portion of switching circuit 132, a unijunctiontransistor 160 has its base one connection coupled through a resistor161 to conductor 152, and its base two connection coupled throughanother resistor 162 to conductor 150. Its emitter is coupled to ajunction point 163. A capacitor 164 is coupled between terminal 163 andconductor 152. A series circuit including a variable resistor 165 and afixed value resistor 166 is coupled between conductor 150 and terminal163. The charging circuit including capacitor 164, resistor 166 and theeffective portion of variable resistor 165 determines the firing time ofunijunction transistor 160, and regulates the frequency of the pulses tobe supplied to the power amplifier circuit 133. Adjustment of themovable tap of variable resistor 165 effects a frequency adjustment ofthe system. The output pulses are supplied from terminal 163 over diode167 to another common point 168. A resistor 170 is coupled betweenconductor 150 and terminal 168. The collector-emitter circuit of an NPNtype transistor 171 is coupled in series between terminal 168 and commonconductor 152. The base of transistor 171 receives a feedback signalover line 172 to regulate the effective impedance of this transistor andmaintain regulation in this circuit.

Terminal 168 is also coupled to the base of another NPN type transistor173, the emitter of which is coupled through a capacitor 174 toconductor 152. The collector of this transistor is coupled through aseries circuit including resistors 175 and 176 to conductor 150. Anotherseries circuit coupled between conductors 150 and 152 includes a diode177, a PNP type transistor 178, and a resistor 180. A series circuitcomprising variable resistor 181, and fixed value resistors 182 and 183is coupled between conductor 152 and the common connection between diode177 and the emitter of transistor 178. The base of transistor 178 iscoupled to the common connection between resistors 175, 176. Thecollector of transistor 178 is coupled to one side of resistor 180, andover diode 184, conductor 185, and resistor 186, to the commonconnection between diode 167 and terminal 163. This is a feedbackconnection to stabilize operation of the switching circuit 132. Inaddition to the common connection between capacitor 174 and the emitterof transistor 173 is coupled to the common connection between resistors182, 183.

Variable resistor 181 provides a duty cycle control. That is, itsadjustment regulates the percentage of conduction, or on" time, oftransistors 173 and 178 of the total period which they would otherwiseconduct by reasons of the pulses provided from unijunction transistor160. Broken line 187 indicates a ganged or mechanical couplingconnection between duty cycle adjust resistor 181 and frequency adjustresistor 165. It is emphasized that this is not a conventional gangedconnection. In one embodiment found suitable for operating a lowhorsepower d-c motor, frequency adjust resistor 165 was set to providecontrol of frequency over a range of from 50 to 1,000 hertz. For thesame system operation, the duty cycle adjustment was from zero to of thepulse time. In accordance with an important aspect of the invention, theduty cycle ganged connection was established such that below the 10%setting, the frequency of the pulses from unijunction transistor wasautomatically raised as the duty cycle value was reduced below 10%. Thisobviates an intermittent or stepping type movement of the d-c motor atlow energization levels. By gradually increasing the frequency as theduty cycle is decreased below 10%, a smooth operation of the motor ismaintained even at very low speed.

The output signals from switching circuit 132 is applied to poweramplifier 133 by passing over conductor 190 to the base of an NPN typetransistor 191, the emitter of which is coupled to conductor 152. Thecollector of transistor 191 is coupled through a series circuitincluding resistors 192 and 193 to conductor 146. A PNP type transistor194 has its base coupled to the common connection between resistors 192,193. Its emitter is coupled over resistor 195 to conductor 146, to diode196 in parallel with resistor 195, to the base of another PNP typetransistor 197, and over conductor 198 to the base of another PNP typetransistor 200. The collector of transistor 194 is coupled to the commonconnection between an output smoothing inductor 201 and the collector oftransistor 197, the emitter of which is coupled over a resistor 202 toconductor 146. The lower or outputterminal of inductor 201 is coupledboth to output conductor 134 and, over capacitor 203, to commonconductor 131. The emitter of transistor 200 is coupled over a seriescircuit including resistors 204, 205 to conductor 146. A capacitor 206is coupled in parallel with resistor 205. The collector of transistor200 is coupled over a series circuit including resistor 207 andcapacitor 208 to conductor 152. From the common connection betweenresistor 207 and capacitor 208 conductor 172 extends a feedbackconnection to the base of transistor 171 in switching circuit 132. Thepower amplifier circuit is straightforward. Those skilled in the artwill appreciate that the signal received over conductor 190 is amplifiedto a higher power level and passed over inductor 201 and conductor 134,both to the different terminals in the switching network, and to thecharge-run switch connections for left motor 11. Switching circuit 135operates exactly the same way as does 132, and in fact receivesenergization over conductors 150, 152. The output signal from switchingcircuit 135 is supplied over conductor 210 to power amp 136. Conductor210 is similar to the conductor 190 between switching circuit 132 andpower amplifier 133. In the output portion of the power amplifier 136,capacitor 154 and output inductor 155 are placed similarly to thecapacitor 203 and inductor 201 in the power amplifier 133. With thisperspective the different switches and their interconnections will nowbe described.

It is initially noted that when energy is supplied over conductor 146 tothe power amplifier 133 it is also passed over conductors 211 and 212 tothe other power amplifier 136. Conductor 211 is coupled to the center ormovable contact 213 of left-right switch 214, which also has fixedcontacts 215, 216. Fixed contact 215 is connected to conductor 137, andfixed contact 216 is connected to conductor 134. A bypass switch 217 isprovided as shown, with its movable contacts 218 and 219 both coupled toconductors 211 and 212. One fixed contact 220 of this switch is coupledto conductor 134, and the other fixed contact 221 is connected toconductor 137.

In FIG. 4A, charge-run switch 140 includes in addition to the contactset 143-145, two additional contact sets 222-224 for the left motor 11,and 225-227 for the right motor 9. In contact set 222-224, the movablecontact 222 is coupled to conductor 134, fixed contact 223 is coupledover conductor 228 to conductor 142, and the other fixed contact 224 iscoupled both to an upper fixed contact in the forward-reverse switch 230and to a lower fixed contact in the same switch. The circuit details ofthe forward-reverse switch 230 for the left motor and theforward-reverse switch 231 for the right motor need not be described,for these doublepole, double-throw switches operate in a conventionalmanner to reverse the polarity of the voltage applied to energize themotor. For the other set of contacts for charge-run switch 140, movablecontact 225 is coupled to conductor 137, fixed contact 226 is coupledover conductor 232 to conductor 142, and fixed contact 227 is coupledboth to an upper contact and to a lower fixed contact of theforward-reverse switch 231 for the right motor 9.

When switch 141 is closed, energy from the positive pole of battery 22is extended over conductor 142, contacts 143, 144, conductor 146, diode147, resistor 148, and conductor 150 to energize power amplifier 133 andswitching circuit 132 in the channel for energizing left motor 11.Energy is also extended from conductor 146 over conductors 211, 212 topower amplifier 136, and the switching circuit 135 is energized overconductors 150, 152. Depending upon the settings of frequency control165 and duty cycle control 181, a variable d-c voltage is passed overinductor 201, conductor 134, contacts 222, 224, and the contacts offorwardreverse switch 230 to energize left motor 11. This circuit iscompleted over conductor 153 to the negative terminal of battery 22.Similarly the output energy from power amplifier circuit 136 passes overconductor 137, contacts 225, 227, the forward contacts offorward-reverse switch 231, the winding of motor 9, and conductor 153back to battery 22.

If the energy level in the circuit including power amplifier 133 andswitching circuit 132 is increased, the left motor is driven faster andthe craft would turn to the right. To incrase the amount of turning tothe right, turn switch 214 can be actuated so the movable contact 213engages fixed contact 216, bypassing power amplifier 133 and switchingcircuit 132. With this switch closed, the energy from the battery flowsover conductor 146, the conductor 21 1, contacts 213, 216 and conductor134 to drive the left motor at the maximum available energy level. Withbypass switch 217 actuated, both movable contacts 218, 219 engage theirrespective fixed contacts 221, 220 to run both motors at the maximumlevel. This bypass switch in effect bypasses the power amplifiers andswitching circuits for both motors.

When it is desired to charge battery 22, charge-run switch 140 isdisplaced from the illustrated position so that movable contact 144engages fixed contact 145, contact 222 now engages contact 223, and theother movable contact 225 engages fixed contact 226. Of course a-cenergy must be supplied to the a-c to d-c channel (such as Channel 1 inFIG. 1), so that the output energy from rectifier 21 in FIG. 4A isapplied betwen conductors 130, 131. The energy from conductor 130 ispassed over contacts 145, 144, and conductor 146 to the power amplifierand switching circuits. The output energy from the bottom of choke 201in power amplifier 133 passes over conductor 134, contacts 222, 223,conductor 228, and the contacts of switch 141 to the top of battery 22.Similarly the output from the other power amplifier 136 passes overconductor 137, contacts 225, 226, conductors 232, 142, and on-off switch141 to the top of battery 22. The negative pole of battery 22 isconnected back to an output conductor of rectifier 21. In this way thebattery can be recharged when the craft is at an installation withsuitable a-c energy.

FIG. 5 shows one suitable configuration of a system for providing ahigher d-c voltage, such as volts, for operating a universal motor loadfrom a source such as battery 22. The system components can be readilysized to accomodate a 12 or 24 volt potential between positive inputconductor 235 and the other input conductor 236. The oscillator orinverter section of this portion of the power supply includes three PNPtype transistors 237,238 and 240, which may be of germanium to handlethe requisite power levels. The collectors of all three transistors arecoupled to input conductor 236. The emitters of transistors 238, 240 arecoupled through resistors 241 and 242 to the common terminal 243 ofprimary winding 244. The lower end of this winding is coupled to inputconnector 235 and to one plate of capacitor 245, the other plate ofwhich is coupled both to the upper end of winding 244 and through aseries circuit including another capacitor 246 and resistors 247, 248 toconductor 236. The base of transistor 237 is coupled to the commonconnection between resistors 247 and 248. This circuit operates in awell known manner when energized to pass an a-c voltage acrosstransformer 250 and induce an a-c signal in secondary winding 251. Thisa-c signal is rectified in the rectifier bridge 252 to provide an outputvoltage between conductors 253, 254. A filter capacitor 255 is connectedacross these output conductors to minimize the ripple in the 120 voltenergization for a universal motor. Such an arrangement can be used withan independent transformer 250, or it can be used as the Channel 3circuit shown in the uppermost portion of FIG. 1. With such anarrangement the same system shown in FIG. 1 could be utilized withChannel 1 to energize a low voltage motor 11, and over the third channelto energize a 120 volt universal motor 12. Thus the flexibility of thesystem is apparent.

FIG. 6 shows another embodiment of the invention, in which a rheostat orvariable resistor 260 replaces the Channel 2 power control andindication portion of the system shown in FIG. 1. In addition torheostat 260 in FIG. 6, three switches 261, 262 and 263 are depicted toperform the functions accomplished by the switching network 10 in FIG 1.In the position shown of switch 261, full battery charging isaccomplished from output rectifier 21 over conductor 264, the contactsof switch 261, and conductor 265 to battery 22. By displacing switch 261to its alternate position, the power from output rectifier 21 is passedthrough the effective portion of rheostat 260 over conductor 266, andthe contacts of switch 263 to battery 22. Switch 263 determines whetherthe battery or the motor will receive the energy passed over rheostat260. The switch 262 has three positions. In the off position there is nooutput energy transferred from the battery 22 to any portion of thecircuit. With switch 262 in its full position, all the battery energy istransferred over conductor 267, the contacts of switch 262, andconductor 268 to run motor 11 at the maximum level. With switch 262displaced to the variable position, the energy is then passed from itscontacts to the effective portion of variable resistor 260, overconductor 266, and the contacts of switch 263 (in its alternateposition) to motor 11. It is recognized that this system is not asefficient as the system of FIG. 1, in that power is dissipated in therheostat 260. In the system of FIG. 1, the only power transferredthrough the power control and indication Channel 2 is the amountrequired, as determined by the setting of potentiometer 32. Accordinglythere is no waste of energy in the system of FIG. 1.

It is also noted that altough only a single left motor 11 and a singleright motor 9 are shown in FIG. 4A, the motor 11 represents a group ofmotors for mounting on the left rear of the boat, and likewise motor 9represents a group of 1, 2, or more motors. Accordingly in the appendedclaims the term motor group refers to a group of motors-l, 2 ormore-connected together to add their total outputs and effectivelyfunction as one motor. It is apparent that no matter the number ofadditional motors connected in parallel with the indicated single motors9 and 11, circuit interconnections and the system operation will beprecisely the same.

While only particular embodiments of the invention have been disclosedand illustrated, it will be apparent to those skilled in the art thevarious modifications and alterations may be made therein. It istherefore the intention in the appended claims to cover all suchmodifications and alterations as may fall within the true spirit andscope of the invention.

What is claimed is:

l. A system for regulating energization of a d-c motor from a batteryand also regulating charging of the battery, comprising:

a switching network, coupled to the battery and to the motor, having aplurality of switches for regulating energy transfer to and from thebattery and to the motor;

a first channel, coupled between an input line for receiving a-c energyand the switching network, includg an input rectifier coupled to theinput line, an oscillator coupled to the input rectifier for providinga-c energy, and an output rectifier connected to receive the a-c energyover a transformer and pass d-c energy to the switching network, thusproviding d-c energy for charging the battery; and

a second channel, connected to receive d-c energy at a constant levelfrom the switching network and to pass d-c energy at a variable powerlevel over the switching network to the motor, thus controlling motorspeed.

2. An energization system as claimed in claim 1, and in which saidsecond channel includes a driver amplifier and a power amplifier coupledin series to provide the variable power level d-c energy, a firstsensing means connected between the switching network and the driveramplifier to provide a first control signal when d-c energy is beingsupplied to the driver amplifier, a second sensing means coupled to theoutput side of the driver amplifier for providing a second controlsignal when the driver is passing energy to the power amplifier, andindicating means coupled both to the first sensing means and to thesecond sensing means, for providing a normal indication only when bothsaid first and second control signals are present.

3. An energization system as claimed in claim 1, in which said firstchannel includes a voltage regulator coupled in series between the inputrectifier and the oscillator, a feedback winding on said transformer,and means for passing a feedback signal from the feedback winding to thevoltage regulator, to provide effective regulation of the batterycharging level notwithstanding changes in load and losses in theoscillator circuit.

4. An energization system as claimed in claim 1, and further comprisinga third channel, connected between the switching network and a secondd-c motor for energizing the second motor from the battery, includingmeans coupled to the switching network for providing an a-c signal fromenergy supplied by the battery, additional windings on said transformer,a converter connected to receive a-c energy over said additionalwindings from the means for production the a-c signals, and a filter,coupled between the converter and the second motor, for reducing the a-cripple in the d-c voltage passed to the motor.

5. A system for regulating energization of a d-c motor from a battery,and also regulating charging of the battery, comprising:

a switching network, coupled to the battery and to the motor, includinga plurality of switches for regulating the motor drive and batterycharging functions;

a first channel connected between an input line for receiving a-c energyand the switching network, including an input rectifier stage coupled tothe a-c input line, an oscillator connected to operate and provide a-cenergy upon energization by the input rectifier, a transformer havingprimary and secondary windings, with the primary winding coupled to theoscillator, an output rectifier coupled between the secondary windingand the switching network to pass d-c energy to the switching networkwhen a-c energy is supplied to the input line; and

a second channel for both controlling the amount of d-c power suppliedto drive the motor or battery and to provide an indication such power isactually being supplied, comprising an input line coupled to theswitching network for receiving a d-c voltage at a constant level, adriver amplifier stage and a power amplifier stage, both coupled to theinput line for receiving constant level d-c energy, and an output linecoupled between the power amplifier and the switching network to returnd-c energy at a level determined by the operation of the driveramplifier stage, thus to afford regulation of the amount of energy forcharging the battery and for driving the motor.

6. An energization system as claimed in claim 5, in which the firstchanned further includes a voltage regulator coupled between the inputrectifier and the oscillator to afford regulation of the energy suppliedto the oscillator, a feedback winding on said transformer, and means forpassing a feedback signal from the feedback winding to the voltageregulator, thus affording regulation which is a function of the loadimposed over the transformer and is virtually independent of the lossesin the oscillator circuit.

7. An energization system as claimed in claim 5, and further comprisinga third channel, connected between said switching network and a secondd-c motor, comprising additional primary and secondary windings on saidtransformer, a second oscillator coupled between the switching networkand said additional primary winding to receive d-c energy from thebattery and pass a-c energy to the additional secondary windings, aconverter coupled to the additional secondary winding for providing d-cenergy, and a filter coupled between the converter and the second motor,thus providing energization of the second motor from the same battery.

8. An energization system as claimed in claim 5, and in which saidsecond channel comprises a resistor coupled between said input line anda reference line, a first transistor having its emitter-base circuitcoupled to opposite ends of said resistor, to provide current flowthrough the emitter-collector path of the first transistor when currentis supplied over the resistor to the driver amplifier stage, andindicator means coupled to said first transistor for providing anoperating signal when current is flowing over the first resistor toenergize the driver amplifier.

9. A system as claimed in claim 8, and further comprising a Zener diodein said second channel, coupled between said reference line and ground,so that the operating signal is provided only when theenergization tothe driver amplifier is at a voltage level at least equal to the voltagedrop across said Zener diode.

10. An energization system as claimed in claim 8, and further comprisinga second transistor having its base coupled through a diode to theoutput line from the driver amplifier stage, and its emitter-collectorpath coupled in series with said indicator means and said firsttransistor, so that the operating signal from the indicator is providedonly when energy is being supplied to the driver amplifier and thedriver amplifier is also passing energy over its output line to thepower amplifier stage.

11. An energization system as claimed in claim 10, in which theindicator means is a lamp, further comprising a photocell positioned toproduce an output signal responsive to the incident light from saidlamp, and a meter coupled to said photocell to provide an indication ofthe illumination level of the photocell, thus providing an indication ofthe operating level of the driver amplifier stage.

12. An energization system as claimed in claim 11, and furthercomprising an alarm, connected for energization when the operatingindication on said meter drops below a predetermined minimum level.

13. A system for regulating energization of a pair of d-c motor groupsfrom a battery and also for regulating charging of the battery,comprising:

a switching network, coupled to the battery and to both motor groups,having a plurality of switches for regulating energy transfer to andfrom the battery and to the motor groups;

a first channel, connected to receive d-c energy from a pair of inputd-c lines and to pass output a-c energy to the switching network,including a first switching circuit connected to provide a pulse signal,and a first power amplifier circuit connected to amplify the pulsesignal for passage through the switching network, thus energizing one ofthe two motor groups; and

a second channel, connected to receive d-c energy over the two input d-clines and to pass output a-c energy to the switching netowork, includinga second switching circuit connected to provide a pulse signal whenenergized by the d-c voltage, and a second power amplifier circuitconnected to amplify the pulse signal for passage through the switchingnetwork to energize the second of the two motor groups, thus providingdrive for both motor groups in the system,

14. An energization system as claimed in Claim 13, and furthercomprising a left-right steering switch connected in said switchingnetwork, including a movable contact coupled to one of the d-c inputconductors, and a pair of fixed contacts each of which is coupled to adifferent conductor for energizing one of the two motor groups, so thatclosure of the left-right switch in one position energizes one of themotor groups at full level and in the other position energizes the otherof the motor group at its full level, to provide a steering function.

15. An energization system as claimed in claim 13, and furthercomprising a bypass switch connected in said switching network,effective when closed to shunt both the first and second channels topass full d-c energization from the input conductors directly to themotor groups for full speed operation.

16. An energization system as claimed in claim 13, and furthercomprising frequency adjusting means in the switching circuit of eachchannel, operable to adjust the frequency of the pulses provided to thepower amplifier, a duty cycle adjust means in each switching circuit,operable to regulate the portion of each pulse actually passed to thepower amplifier, and means for intercoupling the duty cycle adjust andfrequency adjusting means so that at the lower end of the duty cycleadjust range, the frequency of the pulses is gradually incrased toobviate intermittent actuation of the d-c motors.

17. An energization system as claimed in claim 13, and furthercomprising a third channel, connected to receive a-c energy over aninput line and provide d-c energy over a rectifier circuit, and acharge-run switch in said switching network, operable in one position topass d-c energy from the battery to the first and second channels and inthe second position to pass energy from the rectifier circuit to thebattery, thus affording a charge function in the system.

18. A system for regulating energization of a d-c motor from a batteryand also regulating charging of the battery, comprising:

15 16 a switching network, coupled to the battery and to nected toreceive the a-c energy over a transformer motor, having a plurality ofSwitches for Yeguand pass d-c energy to the switching network, thuslatrng energy transfer to and from the battery and providing energy forcharging the battery; and

to the motor;

a first channel, coupled between an input line for receiving a-c energyand the switching network, ineluding an input rectifier coupled to theinput line, varlable Power level dependmg p the Setting of an oscillatorcoupled to the input rectifier for prothe rheostat, t0 the motor 1' t0th battery. vid'mg a-c energy, and an output rectifier cona secondchannel, including a rheostat connected to the switching network, forpassing d-c energy at a

1. A system for regulating energization of a d-c motor from a batteryand also regulating charging of the battery, comprising: a switchingnetwork, coupled to the battery and to the motor, having a plurality ofswitches for regulating energy transfer to and from the battery and tothe motor; a first channel, coupled between an input line for receivinga-c energy and the switching network, includg an input rectifier coupledto the input line, an oscillator coupled to the input rectifier forproviding a-c energy, and an output rectifier connected to receive thea-c energy over a transformer and pass d-c energy to the switchingnetwork, thus providing d-c energy for charging the battery; and asecond channel, connected to receive d-c energy at a constant level fromthe switching network and to pass d-c energy at a variable power levelover the switching network to the motor, thus controlling motor speed.2. An energization system as claimed in claim 1, and in which saidsecond channel includes a driver amplifier and a power amplifier coupledin series to provide the variable power level d-c energy, a firstsensing means connected between the switching network and the driveramplifier to provide a first control signal when d-c energy is beingsupplied to the driver amplifier, a second sensing means coupled to theoutput side of the driver amplifier for providing a second controlsignal when the driver is passing energy to the power amplifier, andindicating means coupled both to the first sensing means and to thesecond sensing means, for providing a normal indication only when bothsaid first and second control signals are present.
 3. An energizationsystem as claimed in claim 1, in which said first channel includes avoltage regulator coupled in series between the input rectifier and theoscillator, a feedback winding on said transformer, and means forpassing a feedback signal from the feedback winding to the voltageregulator, to provide effective regulation of the battery charging levelnotwithstanding changes in load and losses in the oscillator circuit. 4.An energization system as claimed in claim 1, and further comprising athird channel, connected between the switching network and a second d-cmotor for energizing the second motor from the battery, including meanscoupled to the switching network for providing an a-c signal from energysupplied by the battery, additional windings on said transformer, aconverter connected to receive a-c energy over said additional windingsfrom the means for production the a-c signals, and a filter, coupledbetween the converter and the second motor, for reducing the a-c ripplein the d-c voltage passed to the motor.
 5. A system for regulatingenergization of a d-c motor from a battery, and also regulating chargingof the battery, comprising: a switching network, coupled to the batteryand to the motor, including a plurality of switches for regulating themotor drive and battery charging functions; a first channel connectedbetween an input line for receiving a-c energy and the switchingnetwork, including an input rectifier stage coupled to the a-c inputline, an oscillator connected to operate and provide a-c energy uponenergization by the input rectifier, a transformer having primary andsecondary windings, with the primary winding coupled to the oscillator,an output rectifier coupled between the secondary winding and theswitching network to pass d-c energy to the switching network when a-cenergy is supplied to the input line; and a second channel for bothcontrolling the amount of d-c power supplied to drive the motor orbattery and to provide an indication such power is actually beingsupplied, comprising an input line coupled to the switching network forreceiving a d-c voltage at a constant level, a driver amplifier stageand a power amplifier stage, both coupled to the input line forreceiving constant level d-c energy, and an output line coupled betweenthe power amplifier and the switching network to return d-c energy at alevel determined by the operation of the driver amplifier stage, thus toafford regulation of the amount of energy for charging the battery andfor driving the motor.
 6. An energization system as claimed in claim 5,in which the first channed further includes a voltage regulator coupledbetween the input rectifier and the oscillator to afford regulation ofthe energy supplied to the oscillator, a feedback winding on saidtransformer, and means for passing a feedback signal from the feedbackwinding to the voltage regulator, thus affording regulation which is afunction of the load imposed over the transformer and is virtuallyindependent of the losses in the oscillator circuit.
 7. An energizationsystem as claimed in claim 5, and further comprising a third channel,connected between said switching network and a second d-c motor,comprising additional primary and secondary windings on saidtransformer, a second oscillator coupled between the switching networkand said additional primary winding to receive d-c energy from thebattery and pass a-c energy to the additional secondary windings, aconverter coupled to the additional secondary winding for providing d-cenergy, and a filter coupled between the converter and the second motor,thus providing energization of the second motor from the same battery.8. An energization system as claimed in claim 5, and in which saidsecond channel comprises a resistor coupled between said input line anda reference line, a first transistor having its emitter-base circuitcoupled to opposite ends of said resistor, to provide current flowthrough the emitter-collector path of the first transistor when currentis supplied over the resistor to the driver amplifier stage, andindicator means coupled to said first transistor for providing anoperating signal when current is flowing over the first resistor toenergize the driver amplifier.
 9. A system as claimed in claim 8, andfurther comprising a Zener diode in said second channel, coupled betweensaid reference line and ground, so that the operating signal is providedonly when the energization to the driver amplifier is at a voltage levelat least equal to the voltage drop across said Zener diode.
 10. Anenergization system as claimed in claim 8, and further comprising asecond transistor having its base coupled through a diode to the outputline from the driver amplifier stage, and its emitter-collector pathcoupled in series with said indicator means and said first transistor,so that the operating signal from the indicator is provided only whenenergy is being supplied to the driver amplifier and the driveramplifier is also passing energy over its output line to the poweramplifier stage.
 11. An energization system as claimed in claim 10, inwhich the indicator means is a lamp, further comprising a photocellpositioned to produce an output signal responsive to the incident lightfrom said lamp, and a meter coupled to said photocell to provide anindication of the illumination level of the photocell, thus providing anindication of the operating level of the driver amplifier stage.
 12. Anenergization system as claimed in claim 11, and further comprising analarm, connected for energization when the operating indication on saidmeter drops below a predetermined minimum level.
 13. A system forregulating energization of a pair of d-c motor groups from a battery andalso for regulating charging of the battery, comprising: a switchingnetwork, coupled to the battery and to both motor groups, having aplurality of switches for regulating energy transfer to and from thebattery and to the motor groups; a first channel, connected to received-c energy from a pair of input d-c lines and to pass output a-c energyto the switching network, including a first switching circuit connectedto provide a pulse signal, and a first power amplifier circuit connectedto amplify the pulse signal for passage through the switching network,thus energizing one of the two motor groups; and a second channel,connected to receive d-c energy over the two input d-c lines and to passoutput a-c energy to the switching netowork, including a secondswitching circuit connected to provide a pulse signal when energized bythe d-c voltage, and a second power amplifier circuit connected toamplify the pulse signal for passage through the switching network toenergize the second of the two motor groups, thus providing drive forboth motor groups in the system.
 14. An energization system as claimedin claim 13, and further comprising a left-right steering switchconnected in said switching network, including a movable contact coupledto one of the d-c input conductors, and a pair of fixed contacts each ofwhich is coupled to a different conductor for energizing one of the twomotor groups, so that closure of the left-right switch in one positionenergizes one of the motor groups at full level and in the otherposition energizes the other of the motor group at its full level, toprovide a steering function.
 15. An energization system as claimed inclaim 13, and further comprising a bypass switch connected in saidswitching network, effective when closed to shunt both the first andsecond channels to pass full d-c energization from the input conductorsdirectly to the motor groups for full speed operation.
 16. Anenergization system as claimed in claim 13, and further comprisingfrequency adjusting means in the switching circuit of each channel,operable to adjust the frequency of the pulses provided to the poweramplifier, a duty cycle adjust means in each switching circuit, operableto regulate the portion of each pulse actually passed to the poweramplifier, and means for intercoupling the duty cycle adjust andfrequency adjusting means so that at the lower end of the duty cycleadjust range, the frequency of the pulses is gradually increased toobviate intermittent actuation of the d-c motors.
 17. An energizationsystem as claimed in claim 13, and further comprising a third channel,connected to receive a-c energy over an input line and provide d-cenergy over a rectifier circuit, and a charge-run switch in saidswitching network, operable in one position to pass d-c energy from thebattery to the first and second channels and in the second position topass energy from the rectifier circuit to the battery, thus affording acharge function in the system.
 18. A system for regulating energizationof a d-c motor from a battery and also regulating charging of thebattery, comprising: a switching network, coupled to the battery and tothe motor, having a plurality of switches for regulating energy transferto and from the battery and to the motor; a first channel, coupledbetween an input line for receiving a-c energy and the switchingnetwork, including an input rectifier coupled to the input line, anoscillator coupled to the input rectifier for providing a-c energy, andan output rectifier connected to receive the a-c energy over atransformer and pass d-c energy to the switching network, thus providingd-c energy for charging the battery; and a second channel, including arheostat connected to the switching network, for passing d-c energy at avariable power level, depending upon the setting of the rheostat, to themotor or to the battery.